CN107404296B - RF power amplifier, chip and communication terminal based on current detection feedback - Google Patents

Abstract

The invention discloses a radio frequency power amplifier, a chip and a communication terminal based on current detection feedback. The radio frequency power amplifier comprises a multistage amplifying circuit and at least one current detection feedback circuit, wherein the input end of the current detection feedback circuit is connected with the input end of the current stage amplifying circuit of the multistage amplifying circuit through a corresponding resistor, and the output end of the current detection feedback circuit is connected with the input end of at least one stage of amplifying circuit in front of the current stage amplifying circuit. The current detection feedback circuit generates control voltage which changes in a reverse direction with the static working current according to the detected static working current of the current stage amplification circuit, so that the current detection feedback circuit outputs current which changes in a forward direction with the control voltage, the current is input to the input end of at least one stage of amplification circuit in front of the current stage amplification circuit, the static working current of the at least one stage of amplification circuit in front of the current stage amplification circuit is controlled, and the radio frequency power amplifier works in a state of stable gain and output power.

Description

RF power amplifier, chip and communication terminal based on current detection feedback

technical field

The invention relates to a radio frequency power amplifier, in particular to a radio frequency power amplifier based on current detection feedback, and also to an integrated circuit chip and a corresponding communication terminal including the radio frequency power amplifier based on current detection feedback, belonging to radio frequency integrated circuit technology field.

Background technique

At present, the development of wireless communication greatly satisfies people's demand for communication, and this demand further drives the rapid growth of wireless communication terminals around the world. The RF power amplifier is an indispensable functional module in the wireless communication terminal. Its main function is to amplify the transmission power of the communication terminal, so that it still maintains sufficient signal strength when it reaches the base station, so as to achieve the minimum signal-to-noise ratio required for communication, and complete the signal transmission and reception work of the entire communication link.

In a wireless communication system, the main DC power consumption comes from the radio frequency power amplifier. Reducing the power consumption of the radio frequency power amplifier can significantly improve the working time of the system. On the other hand, the performance of the RF power amplifier directly determines the overall performance of the RF circuit. Also, the design of RF power amplifiers usually requires stable gain and output power values.

However, in the implementation of the RF power amplifier, the gain and output power of the RF power amplifier often change in a wide range due to the influence of factors such as process deviation and temperature change. At the same time, considering that the amplitude of the input signal is affected by process deviation and temperature change, the change of the input signal will cause the RF power amplification to change the output power in a wider range. Therefore, it is necessary to perform feedback control on the static working current and output power of the RF power amplifier, so as to suppress the change of the working state of the RF power amplifier caused by the process change, and reduce the influence of the change of the input signal on the working state of the RF power amplifier. Make the RF power amplifier work in a stable state of gain and output power.

SUMMARY OF THE INVENTION

The primary technical problem to be solved by the present invention is to provide a radio frequency power amplifier based on current detection feedback.

Another technical problem to be solved by the present invention is to provide an integrated circuit chip including the radio frequency power amplifier and a corresponding communication terminal.

In order to realize the above-mentioned purpose of the invention, the present invention adopts the following technical scheme:

According to a first aspect of the embodiments of the present invention, a radio frequency power amplifier based on current detection feedback is provided, including a multi-stage amplifier circuit and at least one current detection feedback circuit, the input end of the current detection feedback circuit is connected to the current detection feedback circuit through a corresponding resistance The input end of the amplifier circuit of the current stage in the multi-stage amplifier circuit is connected, and the output end of the current detection feedback circuit is connected to the input end of the at least one stage amplifier circuit in front of the amplifier circuit of the current stage;

The current detection feedback circuit generates a control voltage that changes inversely with the static operating current according to the detected quiescent operating current of the amplifier circuit of this stage, so that the output of the current detection feedback circuit is positive to the control voltage. The current is input to the input terminal of at least one stage of amplifier circuit in front of the amplifier circuit of this stage, so that the static working current of at least one stage of amplifier circuit changes in a positive direction with the current, so as to ensure the radio frequency power The amplifier operates at a steady state of gain and output power.

Preferably, the radio frequency power amplifier further includes at least one power detection feedback circuit, the input terminal of the power detection feedback circuit is connected to the output terminal of a certain stage of amplification circuit located in front of the amplifier circuit of this stage, the The output end of the power detection feedback circuit is connected with the amplifier circuit of this stage and the input end of at least one stage of amplifying circuit located in front of the amplifier circuit of this stage;

The power detection feedback circuit generates a control voltage that changes inversely with the output power according to the detected output power of the amplifier circuit, so that the power detection feedback circuit outputs a current that changes in a forward direction with the control voltage , the current is input to the amplifier circuit of this stage and the input end of at least one stage of amplifier circuit located in front of the stage of amplifier circuit, so that the static operating current of at least one stage of amplifier circuit changes positively with the current, ensuring that the radio frequency power The amplifier operates at a steady state of gain and output power.

Preferably, the current detection feedback circuit includes a first detection circuit and a first feedback circuit, an output end of the first detection circuit is connected to an input end of the first feedback circuit, and an output end of the first detection circuit is connected to the input end of the first feedback circuit. The input end is connected to the input end of the amplifier circuit of this stage through the corresponding resistor, and the output end of the first feedback circuit is connected to the input end of at least one stage of amplifying circuit before the amplifier circuit of this stage.

Preferably, the input end of the first feedback circuit is connected to the output end of the second detection circuit, and the detected output power of the amplifier circuit of this stage is input to the first feedback circuit through the second detection circuit .

Preferably, the power detection feedback circuit includes a second detection circuit and a second feedback circuit, an output end of the second detection circuit is connected to an input end of the second feedback circuit, and an output end of the second detection circuit is connected The input terminal is connected to the output terminal of the amplifier circuit of this stage, and the output terminal of the second feedback circuit is connected to the amplifier circuit of this stage and the input terminal of at least one amplifier circuit located in front of the amplifier circuit of this stage.

Preferably, the first detection circuit is composed of a first resistor, and the second detection circuit is composed of a fifth resistor connected in series with the first capacitor.

Preferably, the second detection circuit is composed of a first capacitor.

Preferably, both the first feedback circuit and the second feedback circuit include two transistors, wherein a second resistor is provided between the collector of the first transistor and the power supply voltage, and the collector of the first transistor is connected to the second resistor. A third resistor is arranged between the bases of the transistors, the collector of the second transistor is connected to the power supply voltage, the base of the first transistor serves as the input end of the feedback circuit, and the emitter of the second transistor serves as the feedback output of the circuit.

Preferably, a bias voltage is provided for the amplifier circuit of this stage and the first transistor of the current detection feedback circuit through a first bias circuit, the first bias circuit includes a transistor, and the transistor has a bias voltage. The collector is connected to the bias voltage, the emitter of the transistor is connected to the base of the first transistor through a first resistor, and the emitter of the transistor is connected to the input end of the amplifier circuit of this stage through a corresponding resistor A resistor is arranged between the base of the transistor and the bias voltage, and two diodes are arranged in series between the base of the transistor and the ground wire.

Preferably, a bias voltage is provided for the first transistor of the power detection feedback circuit through a second bias circuit, the second bias voltage includes a sixth resistor and a seventh resistor, and one end of the sixth resistor Connected to the power supply voltage, the other end of the sixth resistor is connected with one end of the seventh resistor to form an output end of the second bias circuit, and the other end of the seventh resistor is grounded.

Preferably, in the multi-stage amplifying circuit, each stage of the amplifying circuit is a common-emitter amplifying circuit composed of bipolar transistors or CMOS transistors, and a load is provided between each stage of the amplifying circuit and the power supply voltage , the load is a resistance or an inductance, and a capacitor is set between the input end of the amplifying circuit of the latter stage and the output end of the amplifying circuit of the former stage.

According to a second aspect of the embodiments of the present invention, an integrated circuit chip is provided, which includes the above-mentioned radio frequency power amplifier.

According to a third aspect of the embodiments of the present invention, a communication terminal is provided, which includes the above-mentioned radio frequency power amplifier.

The radio frequency power amplifier based on current detection feedback provided by the present invention is used to realize the quiescent working current of the amplifier circuit of this stage according to the detection by setting the current detection feedback circuit, and to generate an inverse of the quiescent working current according to the detected quiescent working current The changing control voltage causes the current detection feedback circuit to output a current that changes positively with the control voltage. The current is input to the input terminal of at least one stage of amplifier circuit in front of the amplifier circuit of this stage through the current detection feedback circuit, so as to control the static working current of at least one stage of amplifier circuit in front of the amplifier circuit of this stage, so that the radio frequency power amplifier can work at the gain and stable output power.

Description of drawings

1 is a schematic circuit diagram of a radio frequency power amplifier based on current detection feedback provided in Embodiment 1 of the present invention;

2 is a schematic circuit diagram of a radio frequency power amplifier based on current detection feedback provided by Embodiment 2 of the present invention;

3 is a schematic circuit diagram of a radio frequency power amplifier based on current detection feedback provided in Embodiment 3 of the present invention;

4 is a schematic circuit diagram of a radio frequency power amplifier based on current detection feedback provided in Embodiment 4 of the present invention;

FIG. 5 is a schematic circuit diagram of a radio frequency power amplifier based on current detection feedback according to Embodiment 5 of the present invention.

Detailed ways

The technical content of the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

The RF power amplifier based on current detection feedback provided by the present invention includes a multi-stage amplifier circuit, a first bias circuit and a detection feedback circuit, the multi-stage amplifier circuit is connected with the first bias circuit, and the first bias circuit is a multi-stage amplifier The circuit provides the bias voltage. The detection feedback circuit includes at least one current detection feedback circuit, or the detection feedback circuit includes at least one current detection feedback circuit and a power detection feedback circuit. Each of the current detection feedback circuit and the power detection feedback circuit is respectively connected with the multi-stage amplifier circuit. Wherein, when the quiescent working current of the input end of the amplifier circuit of this stage increases or decreases for some reason (for example, production process changes), the gain of the radio frequency power amplifier also increases or decreases correspondingly. At this time, the current detection feedback circuit connected to the amplifier circuit of this stage detects and replicates the quiescent working current of the input end of the amplifier circuit of this stage, which increases or decreases accordingly. The generated control voltage is correspondingly decreased or increased, and the decreased or increased control voltage makes the current output by the current detection feedback circuit smaller or larger. The current output by the current detection feedback circuit is input to the input terminal of at least one stage of amplifier circuit in front of the amplifier circuit of this stage, so that the quiescent working current of the input terminal of at least one stage of amplifier circuit in front of the amplifier circuit of this stage correspondingly decreases or increases, resulting in this stage. The gain of at least one stage of amplifying circuit in front of the amplifying circuit decreases or increases accordingly, so as to compensate for the increase or decrease of the gain of the RF power amplifier due to the increase or decrease of the quiescent operating current of the amplifying circuit of this stage, Ensure that the total gain of the RF power amplifier is constant.

When the output power of a certain stage of the amplifier circuit located in front of the amplifier circuit of this stage increases or decreases, the output power of the radio frequency power amplifier also increases or decreases correspondingly. At this time, the power detection feedback circuit connected to a certain stage of the amplifier circuit detects that the output power of a certain stage of the amplifier circuit in front of the amplifier circuit of this stage increases or decreases accordingly, and generates a corresponding current according to the output power, and at the same time A corresponding control voltage is generated according to the current, and the power detection feedback circuit correspondingly reduces or increases the control voltage, so that the current output by the power detection feedback circuit correspondingly decreases or increases. The current output by the power detection feedback circuit can be input to a certain stage of amplifying circuit and multiple input terminals in at least one stage of amplifying circuit located in front of a certain stage of amplifying circuit, so that a certain stage of amplifying circuit and a certain stage of amplifying circuit are located in front of a certain stage of amplifying circuit. The quiescent operating currents of multiple input terminals in the at least one stage of amplifying circuit correspondingly decrease or increase, resulting in a corresponding reduction in the gain and output power of a certain stage of amplifying circuit and at least one stage of amplifying circuit located in front of a certain stage of amplifying circuit or increase, so as to compensate for the increase or decrease of the gain and output power of the RF power amplifier due to the increase or decrease of the output power of a certain stage of the amplifier circuit, and effectively suppress the operation of the RF power amplifier caused by process changes. The change of the state can reduce the influence of the change of the input signal on the working state of the radio frequency power amplifier, so that the radio frequency power amplifier works in a state of stable gain and output power.

Among them, in the radio frequency power amplifier based on power detection feedback provided by the present invention, the positional relationship between the amplifier circuits of each stage in the multi-stage amplifier circuit is based on the current flow of the multi-stage amplifier circuit, that is, the multi-stage amplifier circuit in the present invention is based on the current flow direction. The positional relationship between the front and the back mentioned here is based on the current flow of the multi-stage amplifying circuit.

It should be emphasized that, in the RF power amplifier based on current detection feedback provided by the present invention, the current output by the current detection feedback circuit is input to the input end of at least one stage of amplification circuit in front of the amplifier circuit of this stage, wherein at least one stage of amplification The circuit includes any one-stage or multi-stage amplifier circuit, and at least one-stage amplifier circuit does not include the current-stage amplifier circuit. The current output by the power detection feedback circuit can be input to a certain stage of amplifying circuit and a plurality of input terminals in at least one stage of amplifying circuit located in front of the amplifying circuit, wherein the at least one stage of amplifying circuit includes a certain stage of amplifying circuit and any one. stage or multi-stage amplifier circuit.

In the radio frequency power amplifier based on current detection feedback provided by the present invention, the amplifying circuit is a multi-stage amplifying circuit. Wherein, each stage of the amplifying circuit can be composed of bipolar transistors or CMOS transistors, and a resistance or inductance can be set between each stage of the amplifying circuit and the power supply voltage as a load. 1 to 5, the bipolar amplifying circuit and the three-stage amplifying circuit composed of bipolar transistors (hereinafter referred to as transistors) are taken as examples, and the inductance is used as the load of each stage of the amplifying circuit. The structure and working principle of the RF power amplifier for detection feedback are described in detail.

Example 1

As shown in FIG. 1 , the RF power amplifier based on current detection feedback provided in this embodiment includes a bipolar amplifier circuit, a bias circuit and a current detection feedback circuit. Among them, in the two-stage amplifying circuit, each stage of the amplifying circuit adopts a common-emitter amplifying circuit, that is, the radio frequency input signal is input to the base of the transistor 101 of the first-stage amplifying circuit through a DC blocking capacitor, and the emitter of the transistor 101 is grounded, The inductor 102 is connected between the collector of the transistor 101 and the power supply voltage as the load of the first stage amplifying circuit. The output power of the first-stage amplifying circuit enters the bases of transistors 105a, 105b, and 105c of the second-stage amplifying circuit through the collector of transistor 101 and capacitor 103a, capacitor 103b, and capacitor 103c, respectively. The emitters of the transistors 105a, 105b, and 105c are grounded together, and the inductor 106 is used as the load of the second-stage amplifying circuit. The collector is connected; the output power of the second-stage amplifying circuit is transmitted to the output terminal through the DC blocking capacitor after passing through the collectors of the transistor 105a, the transistor 105b, and the transistor 105c for output.

The first bias circuit includes a transistor 110, a resistor 107, a diode 108, and a diode 109. The collector of the transistor 110 is respectively connected to the bias voltage Vbias and one end of the resistor 107, and the other end of the resistor 107 is respectively connected to the base of the transistor 110 and the diode. The anode of 108 is connected, the cathode of diode 108 is connected to the anode of diode 109, the cathode of diode 109 is grounded, and the emitter of transistor 110 corresponds to the base of transistor 105a, transistor 105b, and transistor 105c through resistor 104a, resistor 104b, and resistor 104c respectively. connect. The first bias circuit is used to provide bias voltages for the transistors 105a, 105b, and 105c of the second-stage amplifier circuit.

The current detection feedback circuit includes a first transistor 111 , a second transistor 115 , a first resistor 112 , a second resistor 113 , a third resistor 114 , and a fourth resistor 116 . The base of the first transistor 111 is connected to the resistor 104 a , the resistor 104 b and the resistor 104 c respectively through the first resistor 112 , and the first bias circuit also provides a bias voltage for the first transistor 111 . The first transistor 111, the second transistor 115, the second resistor, and the third resistor constitute a first feedback circuit, and the first resistor constitutes a first detection circuit. The emitter of the first transistor 111 is grounded, and a second resistor 113 and a third resistor 114 are correspondingly provided between the collector of the first transistor 111 and the power supply voltage and the base of the second transistor 115 . The collector of the second transistor 115 is connected to the power supply voltage, and the emitter of the second transistor 115 is connected to the base of the transistor 101 through the fourth resistor 116 . Since the first resistor 112 and the first transistor 111 constitute the mirror image of the resistor 104a, the resistor 104b, the resistor 104c and the transistor 105a, the transistor 105b and the transistor 105c, the ratio of the first resistor 112 to the resistor 104a, the resistor 104b and the resistor 104c and the third The ratio of a transistor 111 to the transistors 105a, 105b, and 105c enables the first transistor 111 to proportionally replicate the quiescent currents of the transistors 105a, 105b, and 105c. For example, when the quiescent operating currents of the transistors 105a, 105b, and 105c increase for some reason (eg, production process variation), the gain of the RF power amplifier also increases accordingly. At this time, the quiescent operating currents of the transistors 105a, 105b, and 105c replicated on the first transistor 111 of the current detection feedback circuit also increase accordingly, resulting in the control of the second resistor 113 connected to the collector of the first transistor 111. The voltage increases, and the base voltage of the second transistor 115 is decreased through the third resistor 114, so that the current flowing through the second transistor 115 is controlled to decrease accordingly, and the current output by the second transistor 115 is input to the second transistor 115 through the fourth resistor 116. The base of the transistor 101 of the first-stage amplifying circuit reduces the quiescent operating current of the transistor 101 of the first-stage amplifying circuit. The quiescent working current on the first-stage amplifying circuit is reduced, so that the gain of the RF power amplifier is correspondingly reduced, thereby compensating for the increase in the gain of the RF power amplifier due to the increase in the quiescent working current of the second-stage amplifying circuit. , to ensure that the total gain of the RF power amplifier is constant.

In the RF power amplifier based on current detection feedback provided in this embodiment, the current detection feedback circuit detects the quiescent operating current of the second-stage amplifier circuit through the first resistor 112 (first detection circuit), and replicates the current through the first transistor 111 . After the quiescent working current is fed back to the second resistor 113 through the collector of the first transistor 111, the second resistor 113 generates a corresponding control voltage according to the quiescent working current, and controls the current flowing through the second transistor 115 through the third resistor 114. Different currents passing through the second transistor 115 are input to the first-stage amplifying circuit through the fourth resistor 116, so as to control the static working current of the first-stage amplifying circuit and ensure that the RF power amplifier operates in a stable gain state.

Example 2

As shown in FIG. 2 , the RF power amplifier based on current detection feedback provided in this embodiment includes a bipolar amplifier circuit, a first bias circuit, a current detection feedback circuit, and a power detection feedback circuit. Among them, in the two-stage amplifying circuit, the first-stage amplifying circuit includes a transistor 201 and an inductor 202; the second-stage amplifying circuit includes a transistor 205a, a transistor 205b, a transistor 205c and an inductor 206; the first bias circuit includes a transistor 210, a resistor 207, The structures of the diode 208 and the diode 209; the first-stage amplifying circuit, the second-stage amplifying circuit and the first bias circuit are the same as those described in Embodiment 1, and are not repeated here. Similarly, the output power of the first-stage amplifier circuit enters the bases of transistors 205a, 205b, and 205c of the second-stage amplifier circuit through the collector of transistor 201 and capacitors 203a, 203b, and 203c, respectively. The emitter of the transistor 210 of the first bias circuit is respectively connected to the base of the transistor 205a, 205b and 205c through the resistor 204a, the resistor 204b and the resistor 204c respectively, and is implemented as the transistor 205a, the transistor 205b, Transistor 205c provides the bias voltage.

The current detection feedback circuit of the RF power amplifier based on current detection feedback provided by this embodiment includes a first transistor 211 , a second transistor 215 , a resistor 212 , a resistor 213 , a resistor 214 , and a resistor 216 . The structure of the current detection feedback circuit provided in this embodiment is the same as that of the current detection feedback circuit in Embodiment 1, and details are not repeated here. In addition, the first transistor 211, the second transistor 215, the resistor 213, and the resistor 214 constitute a first feedback circuit, and the resistor 212 constitutes a first detection circuit. The current detection feedback circuit detects the quiescent working current of the second-stage amplifier circuit through the resistor 212 (constituting the first detection circuit), and replicates the quiescent working current through the transistor 211, and then feeds it back to the resistor 213 through the collector of the transistor 211. The operating current generates a corresponding control voltage, and controls the current flowing through the transistor 215 through the resistor 214. The different currents flowing through the transistor 215 are input to the first-stage amplifying circuit through the resistor 216 to control the static working current of the first-stage amplifying circuit. Ensure that the RF power amplifier works in a stable state of gain.

The base of the transistor 211 of the current detection feedback circuit provided in this embodiment is sequentially connected to the first capacitor 218 and the fifth resistor 217 to form a power detection feedback circuit. The fifth resistor 217 and the first capacitor 218 are connected in series (the fifth resistor 217 and the first capacitor 218 are connected in series to form a second detection circuit) between the collector of the transistor 201 and the base of the transistor 211 of the first stage amplifier circuit. The output power of the first-stage amplifying circuit is detected through the fifth resistor 217 and the first capacitor 218, and the intensity of the power leaking to the transistor 211 can be controlled. When the RF power amplifier has input power, the output power of the transistor 201 of the first stage amplifying circuit will leak to the base of the transistor 211 through the fifth resistor 217 and the first capacitor 218 . Therefore, when the output power of the first stage amplifying circuit increases, the power leaking to the transistor 211 through the fifth resistor 217 and the first capacitor 218 also increases accordingly, so that the operating current of the transistor 211 also increases accordingly. At this time, the control voltage on the resistor 213 connected to the collector of the transistor 211 will increase, and the base voltage of the transistor 215 will decrease through the resistor 214, thereby controlling the current flowing through the transistor 215 to decrease accordingly. The current output by the transistor 215 is input to the base of the transistor 201 of the first-stage amplifying circuit, so as to reduce the quiescent operating current of the transistor 201 of the first-stage amplifying circuit, thereby reducing the gain of the first-stage amplifying circuit, making the first-stage amplifier circuit The output power of the amplifier circuit is reduced.

Example 3

As shown in FIG. 3 , the RF power amplifier based on current detection feedback provided in this embodiment includes a three-stage amplifier circuit, a first bias circuit, a current detection feedback circuit, and a power detection feedback circuit. Among them, in the three-stage amplifying circuit, the first-stage amplifying circuit includes a transistor 301 and an inductor 302; the second-stage amplifying circuit includes a transistor 304 and an inductor 305; the third-stage amplifying circuit includes a transistor 308a, a transistor 308b, a transistor 308c, and an inductor 309 The first bias circuit includes a transistor 313, a resistor 310, a diode 311 and a diode 312; the structures of the first-stage amplifying circuit and the second-stage amplifying circuit are the same as those of the first-stage amplifying circuit in Embodiment 1, and the third-stage amplifying circuit The structure of the circuit is the same as that of the second-stage amplifying circuit in Embodiment 1, and details are not repeated here. The structure of the first bias circuit is the same as that of the first bias circuit in Embodiment 1, and details are not repeated here. Similarly, the output power of the first-stage amplifying circuit enters the base of the transistor 304 of the second-stage amplifying circuit through the collector of the transistor 301 and the capacitor 303, and the output power of the second-stage amplifying circuit passes through the collector of the transistor 304 and the capacitor 306a. , capacitor 306b, and capacitor 306c respectively enter the bases of transistor 308a, transistor 308b, and transistor 308c of the third-stage amplifier circuit. The emitter of the transistor 313 of the first bias circuit is connected to the bases of the transistors 308a, 308b, and 308c through the resistors 307a, 307b, and 307c, respectively, and is implemented as the transistors 308a, 308b, Transistor 308c provides the bias voltage.

In the current detection feedback circuit of the RF power amplifier based on the current detection feedback provided by this embodiment, the base of the transistor 314 is connected to the resistance 307a, the resistance 307b, and the resistance 307c through the resistance 316 (the resistance 316 constitutes the first detection circuit), respectively. The emitter of the transistor 314 is grounded, and a resistor 315 and a resistor 317 are correspondingly provided between the collector of the transistor 314 and the power supply voltage and the base of the transistor 319 . The collector of transistor 319 is connected to the supply voltage, and the emitter of transistor 319 is connected to the base of transistor 304 through resistor 318 . Among them, the transistor 314 is equivalent to the first transistor 111 (as shown in FIG. 1 ), the transistor 319 is equivalent to the second transistor 115, the resistor 316 is equivalent to the first resistor 112, the resistor 315 is equivalent to the second resistor 113, and the resistor 317 is equivalent to the first resistor 113. Three resistors 114 . In addition, the transistor 314, the transistor 319, the resistor 315, and the resistor 317 also constitute the first feedback circuit. Similarly, since resistor 316 and transistor 314 form mirror images of resistor 307a, resistor 307b, resistor 307c and transistor 308a, transistor 308b and transistor 308c, the ratio of resistor 316 and resistor 307a, resistor 307b and resistor 307c and the ratio of transistor 314 and transistor 308a are designed by designing , transistor 308b, transistor 308c ratio, so that transistor 314 can proportionally replicate the quiescent operating current of transistor 308a, transistor 308b, transistor 308c. The RF power amplifier can detect the static working current of the input terminal of the third-stage amplifier circuit through the resistor 316, copy the static working current through the transistor 314, and then feed it back to the resistor 315 through the collector of the transistor 314. The resistor 315 generates corresponding Control the voltage, and control the current flowing through the transistor 319 through the resistor 317. The different currents flowing through the transistor 319 are input to the input terminal of the second-stage amplifying circuit through the resistor 318, so as to control the static working current of the second-stage amplifying circuit and ensure the first stage. The second stage amplifier circuit works in a stable state of gain.

The power detection feedback circuit of the RF power amplifier based on the current detection feedback provided by this embodiment connects the resistor 320 and the capacitor 321 in series (the resistor 320 and the capacitor 321 are connected in series to form a second detection circuit) in the second stage of the amplifier circuit. Between the collector of the transistor 304 and the base of the transistor 324 of the power detection feedback circuit, the output power of the second stage amplifier circuit is detected through the resistor 320 and the capacitor 321, and the power leakage to the transistor 324 can be controlled. The base of the transistor 324 is connected to one end of the sixth resistor 322 and the seventh resistor 323 respectively, the other end of the sixth resistor 322 is connected to the power supply voltage, and the other end of the seventh resistor 323 is grounded; the sixth resistor 322 and the seventh resistor 323 Transistor 324 is provided with a bias voltage through a voltage divider effect. The sixth resistor 322 and the seventh resistor 323 constitute a second bias circuit. A resistor 325 and a resistor 326 are correspondingly provided between the collector of the transistor 324 and the power supply voltage and the base of the transistor 327 . The collector of the transistor 327 is connected to the power supply voltage, and the emitter of the transistor 327 is connected to the base of the transistor 301 of the first-stage amplifying circuit through a resistor 328 . The transistor 324, the transistor 327, the resistor 325, and the resistor 326 constitute the second feedback circuit. When the RF power amplifier has input power, the output power of the transistor 304 of the second-stage amplifying circuit will leak to the base of the transistor 324 through the resistor 320 and the capacitor 321, thereby changing the working current of the transistor 324. The working current fed back by the electrode generates the corresponding control voltage, the current flowing through the transistor 327 is controlled through the resistor 326, and the current at the output end of the transistor 327 is input to the base of the transistor 301 of the first-stage amplifier circuit through the resistor 328, so as to realize the control of the first-stage amplifier circuit. The static working current of the first-stage amplifier circuit ensures that the RF power amplifier works in a stable state of gain and output power.

Therefore, the RF power amplifier based on the current detection feedback provided in this embodiment can detect the quiescent working current of the input end of the third-stage amplifying circuit through the current-detecting feedback circuit, and control the first stage according to the detected quiescent working current of the third-stage amplifying circuit. The quiescent working current of the second-stage amplifying circuit; the output power of the second-stage amplifying circuit can also be detected through the power detection feedback circuit, and the quiescent current of the first-stage amplifying circuit can be controlled according to the detected output power of the second-stage amplifying circuit, thereby It realizes that the RF power amplifier works in a stable state of gain and output power.

Example 4

As shown in FIG. 4 , the RF power amplifier based on current detection feedback provided in this embodiment includes a three-stage amplifier circuit, a first bias circuit, a current detection feedback circuit, and a power detection feedback circuit. Among them, in the three-stage amplifying circuit, the first-stage amplifying circuit includes a transistor 401 and an inductor 402; the second-stage amplifying circuit includes a transistor 405 and an inductor 404; the third-stage amplifying circuit includes a transistor 408a, a transistor 408b, a transistor 408c, and an inductor 409 ; The first bias circuit includes a transistor 413, a resistor 410, a diode 411 and a diode 412; the structures of the first-stage amplifying circuit, the second-stage amplifying circuit, and the third-stage amplifying circuit are the same as those of the first-stage amplifying circuit in Embodiment 3, The structures of the second-stage amplifying circuit, the third-stage amplifying circuit, and the structure of the first bias circuit are the same as those of the first bias circuit in Embodiment 1, and are not repeated here. Similarly, the output power of the first-stage amplifying circuit enters the base of the transistor 405 of the second-stage amplifying circuit through the collector of the transistor 401 and the capacitor 403, and the output power of the second-stage amplifying circuit passes through the collector of the transistor 405 and the capacitor 406a. , capacitor 406b and capacitor 406c respectively enter the bases of transistor 408a, transistor 408b and transistor 408c of the third stage amplifier circuit. The emitter of the transistor 413 of the first bias circuit is connected to the bases of the transistor 408a, 408b and 408c through the resistor 407a, the resistor 407b and the resistor 407c respectively, and is implemented as the transistor 408a, the transistor 408b, Transistor 408c provides the bias voltage.

The current detection feedback circuit of the RF power amplifier based on the current detection feedback provided by this embodiment includes a transistor 414, a transistor 419, a resistor 415 to a resistor 418, and the transistor 414, the transistor 419, the resistor 415, and the resistor 417 constitute the first feedback circuit , resistor 416 constitutes the first detection circuit; power detection feedback circuit includes transistor 424, transistor 427, resistor 422, resistor 423, resistor 425, resistor 426, resistor 420 and capacitor 421, transistor 424, transistor 427, resistor 425, resistor 426 The second feedback circuit is constituted, the resistor 420 and the capacitor 421 constitute the second detection circuit, and the resistor 422 and the resistor 423 constitute the second bias circuit. The structures of the current detection feedback circuit and the power detection feedback circuit provided in this embodiment are the same as those of the current detection feedback circuit and the power detection feedback circuit in Embodiment 3, and are not repeated here. Similarly, since resistor 416 and transistor 414 constitute mirror images of resistor 407a, resistor 407b, resistor 407c and transistor 408a, transistor 408b and transistor 408c, the ratio of resistor 416 and resistor 407a, resistor 407b and resistor 407c and the ratio of transistor 414 to transistor 408a are designed by designing the resistor 416 and transistor 414. , transistor 408b, transistor 408c ratio, so that transistor 414 can proportionally replicate the quiescent operating current of transistor 408a, transistor 408b, transistor 408c. The current detection feedback circuit detects the quiescent working current of the third-stage amplifier circuit through the resistor 416, and copies the quiescent working current through the transistor 414, and then feeds it back to the resistor 415 through the collector of the transistor 414, and the resistor 415 generates the corresponding control voltage according to the quiescent working current. , and control the current flowing through the transistor 419 through the resistor 417, and the different currents flowing through the transistor 419 are input to the second-stage amplifying circuit through the resistor 418, so as to control the static working current of the second-stage amplifying circuit and ensure the operation of the second-stage amplifying circuit. in a steady state of gain.

In the power detection feedback circuit of the RF power amplifier based on current detection feedback provided by this embodiment, the resistor 420 and the capacitor 421 are connected in series between the collector of the transistor 401 of the first stage amplifier circuit and the base of the transistor 424 of the power detection feedback circuit In between, the output power of the first-stage amplifying circuit is detected through the resistor 420 and the capacitor 421, and the intensity of the power leaking to the transistor 424 can be controlled. The power detection feedback circuit provides a bias voltage for the transistor 424 through the voltage dividing action of the resistor 422 and the resistor 423 . When the RF power amplifier has input power, the output power of the transistor 401 of the first-stage amplifying circuit will leak to the base of the transistor 424 through the resistor 420 and the capacitor 421, thereby changing the working current of the transistor 424. The working current fed back by the electrode generates the corresponding control voltage, the current flowing through the transistor 427 is controlled through the resistor 426, and the current at the output end of the transistor 427 is input to the base of the transistor 401 of the first-stage amplifier circuit through the resistor 428, so as to realize the control of the first-stage amplifier circuit. The static working current of the first-stage amplifier circuit ensures that the RF power amplifier works in a stable state of gain and output power. Therefore, the RF power amplifier based on the current detection feedback provided in this embodiment can detect the quiescent working current of the input end of the third-stage amplifying circuit through the current-detecting feedback circuit, and control the first stage according to the detected quiescent working current of the third-stage amplifying circuit. The quiescent operating current of the second-stage amplifier circuit; the output power of the first-stage amplifier circuit can also be detected through the power detection feedback circuit, and the quiescent current of the first-stage amplifier circuit can be controlled according to the detected output power of the first-stage amplifier circuit, thereby The RF power amplifier can be realized in a stable state of gain and output power.

Example 5

As shown in FIG. 5 , the RF power amplifier based on current detection feedback provided in this embodiment includes a three-stage amplifier circuit, a first bias circuit, a current detection feedback circuit, and a power detection feedback circuit. Among them, in the three-stage amplifying circuit, the first-stage amplifying circuit includes a transistor 501 and an inductor 502; the second-stage amplifying circuit includes a transistor 505 and an inductor 504; the third-stage amplifying circuit includes a transistor 508a, a transistor 508b, a transistor 508c, and an inductor 509 ; The first bias circuit includes a transistor 513, a resistor 510, a diode 511 and a diode 512; The structures of the second-stage amplifying circuit, the third-stage amplifying circuit, and the structure of the first bias circuit are the same as those of the first bias circuit in Embodiment 1, and are not repeated here. Similarly, the output power of the first-stage amplifying circuit enters the base of the transistor 505 of the second-stage amplifying circuit through the collector of the transistor 501 and the capacitor 503, and the output power of the second-stage amplifying circuit passes through the collector of the transistor 505 and the capacitor 506a. , capacitor 506b and capacitor 506c respectively enter the bases of transistor 508a, transistor 508b and transistor 508c of the third stage amplifier circuit. The emitter of the transistor 513 of the first bias circuit is connected to the base of the transistor 508a, the transistor 508b and the transistor 508c through the resistor 507a, the resistor 507b and the resistor 507c respectively, and is realized as the transistor 508a, the transistor 508b, Transistor 508c provides the bias voltage.

The current detection feedback circuit of the RF power amplifier based on current detection feedback provided by this embodiment includes a first feedback circuit composed of a transistor 517 , a transistor 520 , a resistor 518 and a resistor 519 , and a first detection circuit composed of a resistor 514 . . The difference between the structure of the current detection feedback circuit provided in this embodiment and the current detection feedback circuit in Embodiment 1 is that the current detection feedback circuit adopts the resistor 521 and the resistor 522 correspondingly connected to the base of the transistor 505 of the second-stage amplifier circuit. The base of the transistor 501 of the first-stage amplifying circuit realizes that the current output by the transistor 520 is input to the first-stage amplifying circuit and the second-stage amplifying circuit respectively, so as to realize the control of the first-stage amplifying circuit and the second-stage amplifying circuit. quiescent operating current. Specifically, the current detection feedback circuit detects the quiescent working current of the third-stage amplifier circuit through the resistor 514, replicates the quiescent working current through the transistor 517, and feeds it back to the resistor 518 through the collector of the transistor 517, and the resistor 518 generates a corresponding and control the current flowing through the transistor 520 through the resistor 519. The different currents flowing through the transistor 520 are respectively input to the first-stage amplifier circuit and the second-stage amplifier circuit through the resistor 521 and the resistor 522 to realize the control of the first-stage amplifier. The static working current of the circuit and the second-stage amplifier circuit ensures that the RF power amplifier works in a stable state of gain.

The base of the transistor 517 of the current detection feedback circuit provided by the present embodiment is sequentially connected to the resistor 515 and the capacitor 516 (the resistor 515 and the capacitor 516 constitute a second detection circuit) to form a power detection feedback circuit. The resistor 515 and the capacitor 516 are connected in series between the collector of the transistor 505 and the base of the transistor 517 of the second-stage amplifier circuit. The output power of the second-stage amplifying circuit is detected through the resistor 515 and the capacitor 516, and the intensity of the power leaking to the transistor 517 can be controlled. When the RF power amplifier has input power, the output power of the transistor 505 of the second-stage amplifying circuit will leak to the base of the transistor 517 through the resistor 515 and the capacitor 516, thereby changing the working current of the transistor 517. The working current fed back by the electrode generates the corresponding control voltage, the current flowing through the transistor 520 is controlled by the resistor 519, and the current at the output end of the transistor 520 is input to the base electrode of the transistor 501 of the first stage amplifier circuit through the resistor 521 and the resistor 522, respectively. The base of the transistor 505 of the second-stage amplifying circuit can control the static working current of the first-stage amplifying circuit and the second-stage amplifying circuit, and ensure that the RF power amplifier works in a stable state of gain and output power. Therefore, the RF power amplifier based on the current detection feedback provided in this embodiment can detect the quiescent working current of the input terminal of the third-stage amplifying circuit through the current-detecting feedback circuit, and respectively control the quiescent working current according to the detected quiescent working current of the third-stage amplifying circuit. The static working current of the first-stage amplifier circuit and the second-stage amplifier circuit; the output power of the second-stage amplifier circuit can also be detected through the power detection feedback circuit, and the first-stage amplifier circuit can be controlled according to the detected output power of the second-stage amplifier circuit. The quiescent current of the first-stage amplifier circuit and the second-stage amplifier circuit can be adjusted, so that the RF power amplifier can work in a stable state of gain and output power.

The power detection feedback circuit of the RF power amplifier based on the current detection feedback provided by the present invention can also adopt a structure in which a capacitor is replaced by a capacitor and a resistor connected in series between the output end of a certain stage of the amplifier circuit and the input end of the power detection feedback circuit. During this time, the output power of a certain stage of amplifying circuit can be detected through the capacitor. The working principle of the power detection feedback circuit is the same as that described above, and will not be repeated here. It should be emphasized that the transistors in the first bias circuit, the power detection feedback circuit and the current detection feedback circuit of the RF power amplifier based on current detection feedback provided by the present invention are bipolar transistors.

The RF power amplifier based on current detection feedback provided by the present invention connects the input end of the current detection feedback circuit with the input end of the current stage amplifier circuit of the RF power amplifier; After the input end of the stage amplifier circuit is connected, the output end of a certain stage amplifier circuit located in front of the amplifier circuit of this stage is connected with the input end of the power detection feedback circuit; the following effects are achieved:

1. The current detection feedback circuit generates a control voltage that changes inversely with the quiescent operating current according to the detected quiescent operating current at the input of the amplifier circuit of this stage, so that the current detection feedback circuit outputs a current that changes positively with the control voltage.

2. The current output by the current detection feedback circuit is input to the input terminal of at least one stage of amplifier circuit in front of the amplifier circuit of this stage, so that the gain of at least one stage of amplifier circuit in front of the amplifier circuit of this stage is in a positive direction with the current output by the current detection feedback circuit. Therefore, it is possible to compensate for the increase or decrease of the gain of the radio frequency power amplifier due to the increase or decrease of the quiescent operating current of the amplifier circuit of this stage, and to ensure that the total gain of the radio frequency power amplifier is constant.

3. The power detection feedback circuit generates a control voltage that changes inversely with the output power according to the detected output power of a certain stage of amplifying circuit, so that the power detection feedback circuit outputs a current that changes positively with the control voltage.

4. The current output by the power detection feedback circuit is input to a certain stage of amplifying circuit and the input end of at least one stage of amplifying circuit located in front of a certain stage of amplifying circuit, so as to make a certain stage of amplifying circuit and a certain stage of amplifying circuit in front of the amplifying circuit. The gain and output power of at least one stage of amplifying circuit change positively with the current output by the power detection feedback circuit, so as to compensate for the increase or decrease in the gain and output power of the RF power amplifier caused by the increase or decrease of the output power of a certain stage of amplifying circuit. bigger or smaller issues,

To sum up, the RF power amplifier can effectively suppress the change of the working state of the RF power amplifier caused by the process change, and can reduce the influence of the change of the input signal on the working state of the RF power amplifier, so that the RF power amplifier can work at the gain. and the steady state of the output power.

The radio frequency power amplifier based on the current detection feedback provided by the present invention can be used in a radio frequency integrated circuit chip. The specific structure of the radio frequency power amplifier based on current detection feedback in the radio frequency integrated circuit chip will not be described in detail here.

In addition, the above-mentioned radio frequency power amplifier based on current detection feedback can also be used in a communication terminal as an important part of a radio frequency integrated circuit. The communication terminal mentioned here refers to the computer equipment that can be used in the mobile environment and supports various communication standards such as GSM, EDGE, TD_SCDMA, TDD_LTE, FDD_LTE, etc., including mobile phones, notebook computers, tablet computers, car computers, etc. In addition, the technical solutions provided by the present invention are also applicable to other radio frequency integrated circuit applications, such as communication base stations and the like.

The radio frequency power amplifier, chip and communication terminal based on current detection feedback provided by the present invention have been described in detail above. For those skilled in the art, any obvious changes made to it without departing from the essential spirit of the present invention will fall within the protection scope of the patent right of the present invention.

Claims (12)

1. A radio frequency power amplifier based on current detection feedback is characterized by comprising a multistage amplifying circuit and at least one current detection feedback circuit, wherein the input end of the current detection feedback circuit is connected with the input end of a current stage amplifying circuit in the multistage amplifying circuit through a corresponding resistor, and the output end of the current detection feedback circuit is connected with the input end of at least one stage of amplifying circuit in front of the current stage amplifying circuit;

the current detection feedback circuit generates control voltage changing in a reverse direction with the static working current according to the detected static working current of the current-stage amplification circuit, so that the current detection feedback circuit outputs current changing in a forward direction with the control voltage, the current changing in the forward direction is input to the input end of at least one stage of amplification circuit in front of the current-stage amplification circuit, the static working current of at least one stage of amplification circuit changes in the forward direction with the current, and the radio frequency power amplifier is ensured to work in a state of stable gain and stable output power.

2. The current sense feedback-based radio frequency power amplifier of claim 1, wherein:

the radio frequency power amplifier also comprises at least one power detection feedback circuit, the power detection feedback circuit comprises a second detection circuit and a second feedback circuit, the output end of the second detection circuit is connected with the input end of the second feedback circuit, the input end of the second detection circuit is connected with the output end of the current-stage amplification circuit in the multi-stage amplification circuits, and the output end of the second feedback circuit is connected with the current-stage amplification circuit and the input end of at least one-stage amplification circuit positioned in front of the current-stage amplification circuit;

the second feedback circuit generates a control voltage which changes in a reverse direction with the output power according to the detected output power of the current-stage amplification circuit, so that the second feedback circuit outputs a current which changes in a forward direction with the control voltage, and the current which changes in the forward direction is input into the current-stage amplification circuit and an input end of at least one stage of amplification circuit which is positioned in front of the current-stage amplification circuit, so that the static working current of the at least one stage of amplification circuit changes in the forward direction with the current, and the radio frequency power amplifier is ensured to work in a state of stable gain and stable output power.

3. The current sense feedback-based radio frequency power amplifier of claim 2, wherein:

the current detection feedback circuit comprises a first detection circuit and a first feedback circuit, wherein the output end of the first detection circuit is connected with the input end of the first feedback circuit, the input end of the first detection circuit is connected with the input end of the current-stage amplification circuit through the corresponding resistor, and the output end of the first feedback circuit is connected with the input end of at least one stage of amplification circuit in front of the current-stage amplification circuit.

4. The current sense feedback-based radio frequency power amplifier of claim 3, wherein:

and connecting the input end of the first feedback circuit with the output end of the second detection circuit, and inputting the detected output power of the current-stage amplification circuit to the first feedback circuit through the second detection circuit.

5. The current sense feedback-based radio frequency power amplifier of claim 4, wherein:

the first feedback circuit comprises two transistors, wherein a second resistor is arranged between a collector of the first transistor and a power supply voltage, a third resistor is arranged between the collector of the first transistor and a base of the second transistor, the collector of the second transistor is connected with the power supply voltage, the base of the first transistor is used as an input end of the feedback circuit, and an emitter of the second transistor is used as an output end of the feedback circuit.

6. The current sense feedback-based radio frequency power amplifier of claim 2, wherein:

the second feedback circuit comprises two transistors, wherein an eighth resistor is arranged between a collector of a third transistor and a power supply voltage, a ninth resistor is arranged between the collector of the third transistor and a base of a fourth transistor, the collector of the fourth transistor is connected with the power supply voltage, the base of the third transistor is used as an input end of the second feedback circuit, and an emitter of the fourth transistor is used as an output end of the second feedback circuit.

7. The current sense feedback-based radio frequency power amplifier of claim 5, wherein:

and providing bias voltages for the first transistors of the current-stage amplifying circuit and the current detection feedback circuit respectively through a first bias circuit.

8. The current sense feedback-based radio frequency power amplifier of claim 7, wherein:

the first bias circuit comprises a transistor, a collector of the transistor is connected with bias voltage, an emitter of the transistor is connected with a base of the first transistor through a first resistor, the emitter of the transistor is connected with the input end of the current-stage amplification circuit through a corresponding resistor, a resistor is arranged between the base of the transistor and the bias voltage, and two diodes are connected between the base of the transistor and the ground wire in series.

9. The current sense feedback-based radio frequency power amplifier of claim 6, wherein:

and a second bias circuit is used for providing a bias voltage for a third transistor of the second feedback circuit, the second bias circuit comprises a sixth resistor and a seventh resistor, one end of the sixth resistor is connected with a power supply voltage, the other end of the sixth resistor and one end of the seventh resistor are connected together to form an output end of the second bias circuit, and the other end of the seventh resistor is grounded.

10. The current sense feedback-based radio frequency power amplifier of claim 1, wherein:

in the multistage amplifying circuit, each stage of amplifying circuit is a common emitter amplifying circuit composed of bipolar transistors or CMOS transistors, a load is arranged between each stage of amplifying circuit and a power voltage, the load is a resistor or an inductor, and a capacitor is arranged between the input end of the next stage of amplifying circuit and the output end of the previous stage of amplifying circuit.

11. An integrated circuit chip, characterized in that the integrated circuit chip comprises the current detection feedback-based radio frequency power amplifier according to any one of claims 1 to 10.

12. A communication terminal, characterized in that the communication terminal comprises the current detection feedback-based rf power amplifier according to any one of claims 1 to 10.

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